GSK to Acquire BELLUS Health for $2.0 Billion

GSK to Acquire Aiolos Bio

January 9, 2024

Pharmaceuticals

GSK plc has entered an agreement to acquire Aiolos Bio, a clinical-stage biopharmaceutical company focused on unmet needs in respiratory and inflammatory conditions, for a $1 billion upfront payment and up to $400 million in success-based regulatory milestone payments. The deal gives GSK access to Aiolos’ AIO-001, a long-acting anti-TSLP monoclonal antibody (phase II-ready) intended for adult asthma and potentially additional indications.

Gilead Sciences To Acquire Arcellx for $7.8 Billion to Strengthen CAR T-Cell Portfolio

February 21, 2026

Biotechnology

Gilead Sciences entered into a definitive agreement to acquire Arcellx, Inc. for $115 per share in cash plus a contingent value right of $5 per share, implying an equity value of about $7.8 billion. The deal is designed to give Gilead full control of Arcellx’s anito-cel (anito-cabtagene autoleucel) BCMA-directed CAR T therapy, eliminating profit-sharing and related payments while accelerating development and commercialization.

GSK to Acquire IDRx in Up-to $1.15 Billion Deal

January 15, 2025

Biotechnology

GSK has entered into an agreement to acquire IDRx, a Boston-based clinical-stage biopharmaceutical company focused on precision therapeutics for GIST. The deal includes an upfront payment of $1 billion plus a potential additional $150 million success-based regulatory milestone payment.

Nexelis Acquires GSK Vaccines Clinical Bioanalytical Laboratory (Marburg)

January 20, 2021

Biotechnology

Nexelis, a portfolio company of Ampersand Capital Partners, has signed an asset purchase agreement to acquire GSK's GCLP-certified clinical bioanalytical laboratory in Marburg, Germany. Approximately 80 scientists and analysts will transfer to Nexelis, which also entered a five-year strategic collaboration with GSK to continue supporting vaccine development while expanding Nexelis' assay development and high-throughput clinical testing capabilities in Europe.

GSK Acquires Elsie Biotechnologies for up to $50M

June 6, 2024

Biotechnology

GSK plc has completed the acquisition of Elsie Biotechnologies, a San Diego–based oligonucleotide-focused biotechnology company, for up to $50 million. The deal integrates Elsie's discovery, synthesis and delivery capabilities into GSK's oligonucleotide R&D platform to accelerate development of therapeutics for chronic hepatitis B, steatotic liver disease and other difficult-to-treat diseases.

GSK to Acquire Sierra Oncology for $1.9 Billion

April 13, 2022

Biotechnology

GlaxoSmithKline plc (GSK) has entered into an agreement to acquire late-stage biopharmaceutical company Sierra Oncology, Inc. for $1.9 billion (approximately $55 per share in cash). The acquisition is intended to bring Sierra’s lead asset momelotinib—an investigational targeted therapy for myelofibrosis and anemia—into GSK’s specialty medicines portfolio.